Note: Descriptions are shown in the official language in which they were submitted.
CA 02619323 2008-01-28
Attorney Docket: 630-269US
507016-US-NP3 (Abramson)
Private-Branch Exchange that Provides Call Bridging to an Off-Premises
Terminal in the Presence of a Third-Party Application
Field of the Invention
[ooo1] The present invention relates to telecommunications in general, and,
more
particularly, to computer-telephony integration.
Background of the Invention
[0002] A business that desires to provide employees at one location with
telephones
has, in general, two options. First, the business can acquire one telephone
and one
telephone line per employee from the telephone company. Second, the business
can
acquire one telephone per employee, a small number of telephone lines from the
telephone
company, and a piece of equipment that enables the employee's telephones to
share the
small number of telephone lines. In general, the second option is
substantially less
expensive than the first option, and the piece of equipment that enables the
employees'
telephones to share the small number of telephone lines is called a "private-
branch
exchange" or "PBX." Private-branch exchanges are also capable of providing
valuable
telecommunications features to their users.
Summary of the Invention
[0003] The present invention enables a valuable capability of a
telecommunications
system. In the prior art, one feature of a telecommunications system enables a
user to pair
a desk set that is an extension of a private-branch exchange with a cell phone
that is
accessible via the Public Switched Telephone Network. The feature enables an
active call
that is between the desk set and another party, to be transferred to the
user's cell phone.
This is advantageous because a user who is initially on a call at her desk
set, but needs to
get to somewhere else (e.g., a meeting, the airport, home, etc.) before the
call is over, is
able to continue the call by transferring it to her cell phone.
[0004] The illustrative embodiment of the present invention also provides the
transfer feature, but does so when a third party serves as a front-end to the
cell phone and,
as such, acts as an agent to the cell phone in controlling calls to and from
the cell phone.
Such a third party includes a computer-telephony integration (CTI) application
in a
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telephone telemarketing center, which concurrently handles many active
telephone calls.
Third-party CTI applications are often not inherently integrated with some or
all of the
features provided by the co-existing private-branch exchanges. The
illustrative
embodiment enables such CTI applications to interwork with legacy private
branch
exchanges or other equipment.
[ooos] The illustrative embodiment comprises receiving a request to bridge an
active
call that exists between a telephone number D and a telephone number T, to a
telephone
number C; allocating, from a pool of ports, a port P that is capable of
emulating a telephone
extension; and establishing a resultant call between the telephone number T
and the
telephone number C, the resultant call being based on the active call and on
at least one
precursor call having been made that includes port P; wherein the telephone
number C is
associated with the telephone number D in a data structure and is within the
address space
of the Public Switched Telephone Network; and wherein the telephone number D
is within
the address space of a private-branch exchange.
Brief Descriation of the Drawings
[0006] Figure 1 depicts a schematic diagram of the salient components of
telecommunications system 100 in accordance with the illustrative embodiment
of the
present invention.
[0007] Figure 2 depicts a flowchart of the salient task performed by the
illustrative
embodiment of the present invention.
[ooos] Figure 3 depicts a flowchart of the salient tasks of task 201 in
accordance
with the illustrative embodiment of the present invention.
[ooo9] Figures 4a, 4b, 4c, and 4d depict graphs of the salient components of
the
precursor calls and resultant calls.
[ooio] Figure 5 depicts a flowchart of the salient task performed by the
illustrative
embodiment in accomplishing task 301.
[ooii] Figure 6 depicts a flowchart of the salient tasks performed by the
illustrative
embodiment in accomplishing task 302.
[00i2] Figure 7 depicts a flowchart of the salient task performed by the
illustrative
embodiment in accomplishing task 303.
[0013] Figure 8 depicts a flowchart of the salient task performed by the
illustrative
embodiment in accomplishing task 304.
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[0014] Figure 9 depicts a flowchart of the salient task performed by the
illustrative
embodiment in accomplishing task 305.
[oois] Figure 10 depicts a flowchart of the salient task performed by the
illustrative
embodiment in accomplishing task 307.
Detailed Description
[0016] Telecommunications System 100 - Fiuure 1 depicts a schematic diagram
of the salient components of telecommunications system 100 in accordance with
the
illustrative embodiment of the present invention. Telecommunications system
100
comprises affiliated PSTN terminal 101, unaffiliated PSTN terminal 102,
private-branch
exchange (PBX) terminal 103, private-branch exchange (PBX) telephone system
104, Public
Switched Telephone Network 105, and computer-telephony integration (CTI)
application 106 interconnected as shown.
[0017] Although the illustrative embodiment comprises one affiliated PSTN
telecommunications terminal, one unaffiliated PSTN telecommunications
terminal, and one
PBX telecommunications terminal, it will be clear to those skilled in the art,
after reading
this disclosure, how to make and use alternative embodiments of the present
invention that
comprise any number of affiliated PSTN telecommunications terminals,
unaffiliated PSTN
telecommunications terminals, and PBX telecommunications terminals.
[oois] Affiliated PSTN terminal 101 is a telecommunications terminal that
corresponds to telephone number C in address space 111 of Public Switched
Telephone
Network 105. Terminal 101 is off-premises in relation to the on-premises
enterprise region
served by PBX telephone system 104. It will be clear to those skilled in the
art, after
reading this specification, how to make and use alternative embodiments of the
present
invention in which affiliated PSTN terminal 101 corresponds to a telephone
number in the
address space of a private branch exchange, such as, for example and without
limitation,
address space 112 of private branch exchange 104. In accordance with the
illustrative
embodiment, affiliated PSTN terminal 101 is a wireless terminal (e.g.,
cellular telephone,
etc.). It will be clear to those skilled in the art, after reading this
disclosure, how to
make and use alternative embodiments of the present invention in which
affiliated PSTN
terminal 101 is a wireline terminal. It will be clear to those skilled in the
art how make and
use affiliated PSTN terminal 101.
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[ooz9] Unaffiliated PSTN terminal 102 is a telecommunications terminal that
corresponds to telephone number T in address space 111 of Public Switched
Telephone
Network 105. It will be clear to those skilled in the art, after reading this
disclosure, how to
make and use alternative embodiments of the present invention in which
unaffiliated PSTN
terminal 102 corresponds to a telephone number in the address space of a
private branch
exchange, such as, for example and without limitation, address space 112 of
private branch
exchange 104. In accordance with the illustrative embodiment, unaffiliated
PSTN
terminal 102 is a wireless terminal (e.g., cellular telephone, etc.). It will
be clear to those
skilled in the art, after reading this disclosure, how to make and use
alternative
embodiments of the present invention in which unaffiliated PSTN terminal 102
is a wireline
terminal. It will be clear to those skilled in the art how to make and use
unaffiliated PSTN
terminal 102.
[0020] PBX terminal 103 is a telecommunications terminal that corresponds to
telephone number D in address space 112 of private branch exchange 104. It
will be clear
to those skilled in the art, after reading this disclosure, how to make and
use alternative
embodiments of the present invention in which PBX terminal 103 corresponds to
a
telephone number in address space 111 of the Public Switched Telephone Network
or the
address space of another private branch exchange. In accordance with the
illustrative
embodiment, terminal 103 is a wireline terminal. It will be clear to those
skilled in the art,
after reading this disclosure, how to make and use alternative embodiments of
the present
invention in which terminal 103 is a wireless terminal. It will be clear to
those skilled in the
art how to make and use terminal 103.
[0021] Private-branch exchange 104 is a switch that provides
telecommunications
service to PBX terminal 103. Private branch exchange 104 comprises a data
structure that
associates the telephone number that corresponds to the PBX terminal 103 with
the
telephone number that corresponds to affiliated terminal 101. An example of
such a data
structure is depicted in Table 1.
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Telephone Number That Corresponds Telephone Number That Corresponds to
to PBX Terminal 103 Affiliated Terminal 101
D C
Table 1 - Data Structure That Associates the Telephone Number That Corresponds
to PBX Terminal 103 with the Telephone Number That Corresponds to Affiliated
Terminal 101
Although the illustrative embodiment associates one pair of telephone numbers,
it will be
clear to those skilled in the art, after reading this disclosure, how to make
and use
alternative embodiments of the present invention that associate any number of
pairs.
[0022] Private-branch exchange 104 further comprises call-resource pool 107,
which
in turn comprises a plurality of CTI ports. It will be clear to those skilled
in the art, after
reading this disclosure, how to make and use embodiments of the present
invention that
comprise any number of CTI ports. Each port P is a logical point of connection
that is
capable of emulating a telephone extension, at least in the sense that within
private-branch
exchange 104, a call can be placed to a port, placed from a port, put on hold
at a port, or
transferred to or from a port. The particular telephone extension that a given
port emulates
might be known only to CTI application 106 and to private-branch exchange 104
itself, but
not necessarily to any other device in system 100. At least one of CTI
application 106 and
private-branch exchange 104 is able to monitor the busy/idle status of each
port P.
[0023] As those who are skilled in the art will appreciate, provisioning a
greater
number of ports will tend to result in a lower blocking level in the handling
of calls, but can
require additional resources with an associated additional cost. It will be
clear to those
skilled in the art how to determine an optimal provisioning of ports, for a
given blocking
level versus cost tradeoff. Additionally, it will be clear to those skilled in
the art how to
provision and administer the ports of pool 107.
[0024] In accordance with the illustrative embodiment, the operation of
private-
branch exchange 104 and PBX terminal 103 can be directed by computer-telephony
integration application 106 in well-known fashion. The details of how to make
and use
private-branch exchange 104 are described in detail below and in the following
drawings.
[0025] Public Switched Telephone Network 105 is the public telephone network.
It
will be clear to those skilled in the art how to make and use Public Switched
Telephone
Network 105.
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[0026] Computer-telephony integration (CTI) application 106 is a combination
of
hardware and software that directs the operation of private-branch exchange
104 and PBX
terminal 103. In particular, the CTI application provides the functionality
described in detail
below and in the accompanying figures. It will be clear to those skilled in
the art, after
reading this disclosure, how to make and use alternative embodiments of the
present
invention, in which CTI application 106 is absent and its functionality is
performed by
private-branch exchange 104 or by a natural person or by a combination of
private-branch
exchange 104 and by a natural person.
[0027] In accordance with the illustrative embodiment, CTI application 106
runs on
an independent, general-purpose processor. It will be clear to those skilled
in the art, after
reading this disclosure, how to make and use alternative embodiments of the
present
invention in which CTI application 106 runs on an adjunct processor of private-
branch
exchange 104, a component of one or more of the terminals of telecommunication
system 100, or on a special-purpose processor. The details of how to make and
use CTI
application 106 are described in detail below and in the following drawings.
[0028] Operation of the Illustrative Embodiment - Figure 2 depicts a flowchart
of the salient task performed by the illustrative embodiment of the present
invention.
[00293 Task 201 comprises extending an active call that is between telephone
number T to telephone number D, to telephone number C. The details of how to
perform
task 201 are described in detail below and with respect to the following
drawings.
[0030] Establish Resultant Call - Figure 3 depicts a flowchart of the salient
tasks
of task 201 in accordance with the illustrative embodiment of the present
invention.
[0031] At task 301, CTI application 106 receives notification that an active
call exists
that includes telephone number D (i.e., that has D as a party to the call).
Figure 4a depicts
a graph of the salient components of active call 421; in this example, active
call 421 was
placed from telephone number T to telephone number D and, as a result,
comprises
connections 401-1 and 401-2. After receiving the notification of the active
call,
application 106 notifies affiliated PSTN terminal 101 of the call. It will be
clear to those
skilled in the art how to make and use embodiments of the present invention
that
accomplish task 301.
[0032] At task 302, CTI application 106 receives a request from terminal 101,
the
affiliated PSTN terminal, to bridge the active call to telephone number C, a
telephone
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number of terminal 101. For the purposes of this specification and the
appended claims,
the term "bridge" can mean either to join telephone number C to the call
without dropping
any of the parties already on the call or to transfer or switch the call to
telephone
number C, in the process dropping telephone number D from the call. As a
result of
receiving the request, application 106 directs private-branch exchange 104 to
establish a
first precursor call to telephone number D from a CTI port, and to enable the
extending of
the call to the telephone number of the affiliated PSTN terminal (i.e.,
telephone number C).
The details of task 302 are described in detail below and in the accompanying
figures.
[0033] In response to task 302, private-branch exchange 104 establishes at
task 303
the first precursor call that includes telephone number D and telephone number
C.
Figure 4b depicts a graph of the salient components of active call 421 and
first precursor
call 422, which comprises connections 402-1 and 402-2. The details of task 303
are
described in detail below and in the accompanying figures.
[0034] At task 304, CTI application 106 directs private-branch exchange 104 to
establish a second precursor call from telephone number D to port P. In
accordance with
the illustrative embodiment, task 304 is distinct from task 302. It will be
clear to those
skilled in the art, however, after reading this disclosure, how to make and
use alternative
embodiments of the present invention in which tasks 302 and 304 are combined
or
concurrent or performed in the opposite order. It will be clear to those
skilled in the art
how to make and use embodiments of the present invention that accomplish task
304.
[003s] In response to task 304, private-branch exchange 104 establishes at
task 305, the second precursor call from telephone number D to port P. Figure
4c depicts a
graph of the salient components of active call 421, first precursor call 422,
and second
precursor call 423, which comprises connection 403-1. In accordance with the
illustrative
embodiment, task 303 is performed before task 305. It will be clear to those
skilled in the
art, after reading this specification, how to make and use alternative
erribodiments of the
present invention in which task 303 and task 305 are performed concurrently or
in the
opposite order. It will be clear to those skilled in the art how to make and
use
embodiments of the present invention that accomplish task 305.
[0036] At task 306, CTI application 106 directs private-branch exchange 104 to
combine all three calls (i.e., one active and two precursor) to generate a
resultant call
between telephone number T and telephone number C while bridging telephone
number D
to the call. In accordance with the illustrative embodiment, task 306 is
distinct from
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task 302 and task 304. It will be clear to those skilled in the art, after
reading this
disclosure, how to make and use alternative embodiments of the present
invention in which
task 302, task 304, and task 306 are combined or concurrent or performed in
any order. It
will be clear to those skilled in the art how to make and use embodiments of
the present
invention that accomplish task 306.
[0037] In response to task 306, private-branch exchange 104 combines, at task
307,
all three calls to generate the resultant call between telephone number T and
telephone
number C while bridging telephone number D to the call. In accordance with the
illustrative
embodiment, the combination of the three precursor calls results in two-party
resultant
call 424 comprising connections 401-1, 401-2, and 402-2, as depicted in Figure
4d.
Task 307 is described in detail below and in the accompanying figures.
[0038] Notification of Active Call - Figure 5 depicts a flowchart of the
salient
tasks performed by the illustrative embodiment in accomplishing task 301.
[0039] At task 501, CTI application 106 receives notification of an active
call between
telephone numbers T and D.
[0040] At task 502, CTI application 106, in response to having received the
active-call notification, notifies the corresponding affiliated PSTN terminal
(i.e., terminal 101) about the call.
[0041] Direct the Establishment of First Precursor Call - Ficaure 6 depicts a
flowchart of the salient tasks performed by the illustrative embodiment in
accomplishing
task 302.
[0042] At task 601, CTI application 106 receives a request from the affiliated
telecommunications terminal to be bridged to the active call. As those who are
skilled in
the art will appreciate, the terminal can transmit the request to application
106 either
spontaneously or as the result of having received notification of the active
call in
conjunction with task 502.
[0043] At task 602, CTI application 106 determines that a port from pool 107,
namely port P, is available to set up one or more precursor calls. Application
106 directs
private-branch exchange 104 to: (i) enable a call made to telephone number D
to be
extended to the telephone number of the affiliated PSTN terminal (i.e.,
telephone
number C); (ii) establish the first precursor call from selected port P to
telephone
number D; and (iii) place the first precursor call on hold. It will be clear
to those skilled in
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the art how to make and use embodiments of the present invention that
accomplish
task 302.
[0044] In some embodiments, directing exchange 104 comprises transmitting one
or
more messages that: (i) direct the enabling of the extending of calls that are
placed to
telephone number D, to a telephone number of an affiliated terminal; (ii)
direct the placing
of the first precursor call; or (iii) direct the placing of the first
precursor call on hold, or
direct in some combination thereof.
[0045] Establish First Precursor Call - Fiaure 7 depicts a flowchart of the
salient
tasks performed by the illustrative embodiment in accomplishing task 303.
[00461 At task 701, private-branch exchange 104 is directed by CTI application
106,
via one or more received messages, to establish a first precursor call from
selected port P to
telephone number D and to place the first precursor call on hold. In
accordance with the
illustrative embodiment, CTI application 106 directs private-branch exchange
104 to
establish the first precursor call.
[0047] In some embodiments, the messages that exchange 104 receives comprise
one or more messages that: (i) direct the enabling of the extending of calls
that are placed
to telephone number D, to a telephone number of an affiliated terminal; (ii)
direct the
placing of the first precursor call; or (iii) direct the placing of the first
precursor call on hold,
or direct in some combination thereof.
[0048] At task 702, private-branch exchange 104 allocates port P to be used
for
originating the call to telephone number D.
[00491 At task 703, private-branch exchange 104 enables the extending to
telephone
number C of one or more calls made to telephone number D. Exchange 104 then
establishes the first precursor call from port P to telephone number D, in
well-known
fashion.
[oo5o] At task 704, in response to the call to telephone number D and to
having
enables the call extension capability, private-branch exchange 104 extends the
first
precursor call to telephone number C, in well-known fashion.
[oosi] At task 705, private-branch exchange 104 places the first precursor
call on
hold, in well-known fashion.
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[0052] Direct the Establishment of Second Precursor Call - Figure 8 depicts a
flowchart of the salient tasks performed by the illustrative embodiment in
accomplishing
task 304.
[0053] At task 801, CTI application 106 directs private-branch exchange 104 to
establish a second precursor call from telephone number D to port P. It will
be clear to
those skilled in the art how to make and use embodiments of the present
invention that
accomplish task 304.
[0054] In some embodiments, directing exchange 104 comprises transmitting one
or
more messages that: (i) direct the placing of the active call on hold; (ii)
direct the placing of
the second precursor call; (iii) direct the answering of the second precursor
call; or (iv)
direct the placing of the second precursor call on hold, or direct in some
combination
thereof.
[ooss] Establish Second Precursor Call - Figure 9 depicts a flowchart of the
salient tasks performed by the illustrative embodiment in accomplishing task
305.
[0056] At task 901, private-branch exchange 104 is directed by CTI application
106
to establish a second precursor call from telephone number D to port P, in
accordance with
the illustrative embodiment.
[0057] In some embodiments, the messages that exchange 104 receives comprise
one or more messages that: (i) direct the placing of the active call on hold;
(ii) direct the
placing of the second precursor call; (iii) direct the answering of the second
precursor call;
or (iv) direct the placing of the second precursor call on hold, or direct in
some combination
thereof.
[ooss] At task 902, exchange 104 places the active call on hold.
[oos9] At task 903, private-branch exchange 104 establishes the second
precursor
call from telephone number.D to port P, in well-known fashion.
[0060] In some embodiments, exchange 104 then answers the second precursor
call
and places the precursor call on hold.
[0061] Combining the Calls - Figure 10 depicts a flowchart of the salient task
performed by the illustrative embodiment in accomplishing task 307.
[0062] At task 1001, private-branch exchange 104 retrieves the active call
(i.e., the
call between telephone number T and telephone number D), in well-known
fashion.
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[0063] At task 1002, private-branch exchange 104 merges the second precursor
call
(i.e., from telephone number D to port P) with the active call at telephone
number D, in
well-known fashion.
[0064] At task 1003, private-branch exchange 104 merges the first precursor
call
(i.e., from port P to telephone number D, extended to telephone number C) with
the
already-merged active call (i.e., between telephone number T and port P), in
well-known
fashion; the effect of this is to create the resultant call. Exchange 104 then
drops port P as
a result of the merging.
[0065] At task 1004, private-branch exchange 104 deallocates port P, thereby
enabling the port to be reused to support future calls that are controlled via
CTI
application 106.
[0066] It is to be understood that the above-described embodiments are merely
illustrative of the present invention and that many variations of the above-
described
embodiments can be devised by those skilled in the art without departing from
the scope of
the invention. For example, in this Specification, numerous specific details
are provided in
order to provide a thorough description and understanding of the illustrative
embodiments
of the present invention. Those skilled in the art will recognize, however,
that the invention
can be practiced without one or more of those details, or with other methods,
materials,
components, etc.
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